Which statement is true regarding the cutoff of a brake?

The true statement regarding the cutoff of a brake is that cutting out must be reported to the proper authority. This ensures that there is proper communication and documentation of the changes in the braking system, which is critical for safety and operational integrity. Notifying the appropriate personnel helps maintain awareness of the train's braking capabilities, allowing for proper safety measures to be implemented and ensuring compliance with regulations.

In a railroad context, cutting out a brake refers to the process of removing a particular brake from operation, which can significantly affect train handling and stopping distances. Therefore, reporting this action is essential to prevent potential accidents or incidents that could arise from a misunderstanding of the train's braking power.

The other statements fail to emphasize the need for accountability and safety in operations. A brake cannot be cut out arbitrarily or without proper notification, as this can lead to dangerous situations. Additionally, it is not just key train brakes that need to be reported; any brake cutout should be communicated to maintain safety standards across the entire operation.